A RNZAF Orion has been dispatched to the area where the ferry sank. Photo / Supplied

A survivor has described how the Tongan ferry Princess Ashika overturned and all the women and children perished, as searchers combed waters for survivors this afternoon.

The Princess Ashika was heading from Nuku'alofa to Ha'afeva, in the Nomuka Islands group, when it issued a mayday call just before 11pm last night, quickly followed by the release of a distress beacon.

Ha'afeva man Siaosi Lavaka told the Matangi Tonga website he saw one body recovered and only the men had reached the lifeboats after the MV Princess Ashika was overturned by heavy seas.

He feared none of the women and children had survived.

One of the ships helping in the search for survivors, the MV Pulupaki, arrived at Ha'afeva island this morning with 50 male survivors.

"No women or children made it," Siaosi told the Tongan news agency by cellphone.

Siaosi was travelling with his mother Lavinia, who is still missing.

He said waves went into the lower deck of the ferry where the crew were. The ferry rocked and he believed this caused the cargo to move to one side. The ferry then began to overturn and some passengers jumped off.

"We woke up to the sound of shouting and we jumped off."

There were nine lifeboats and Siaosi said seven were all filled with male survivors. When they got onto the lifeboat the ferry subsided.

There were two other the lifeboats, one was empty and the other lifeboat had already drifted off. He believed the women and children were sleeping and all were stuck inside the ferry when it went down.

There are conflicting reports on how many people were on board.

The website also published a list of known survivors, 27 crew and 23 passengers from a total of 96 people, which it said was supplied by the Shipping Corporation of Polynesia.

New Zealand's Rescue Coordination Centre (RCCNZ) said there were a total of 86 on board and 53 had been picked up so far.

There were unconfirmed reports the body of a male European had been found, and a surviving crew member believed two Europeans and one Japanese were among the missing passengers.

A RCCNZ spokeswoman told NZPA Tongan police were speaking to the captain, Maka Tuputupu, who was one of those saved. That would provide some clarity on how the sinking happened, but the main focus at the moment was finding survivors.

The Tongan navy ship Pangai was searching, along with three commercial vessels, and another commercial vessel would join the search soon, she said.

By midday, an RNZAF Orion had covered nearly half of the 207sq km search area, pinpointing the sinking about 86km northeast of Nuku'alofa.

A second Orion was due to take over this afternoon.

The crew reported good search conditions and a trail of debris from the sunken vessel stretching about 15km.

A balmy water temperature of 25degC would aid the survival chances of those still in the water and a two- to three-metre swell was forecast to ease.

The Princess Ashika, built in Japan in 1970, had been plying Tongan waters for only a few weeks and was just a stop-gap measure ahead of a new ferry coming into service.

The ferry was brought to Tonga from Fiji this year to replace the old 'Olovaha passenger ferry because of fears that the 'Olovaha was no longer safe.